A small internal class used by the physics system to represent a contact point for wheel friction resolution. It stores the two rigid bodies, world-space friction contact position and direction, maximum impulse and computes the inverse of the jacobian diagonal term used during impulse solving.
/* * C# / XNA port of Bullet (c) 2011 Mark Neale <[email protected]> * * Bullet Continuous Collision Detection and Physics Library * Copyright (c) 2003-2008 Erwin Coumans http://www.bulletphysics.com/ * * This software is provided 'as-is', without any express or implied warranty. * In no event will the authors be held liable for any damages arising from * the use of this software. * * Permission is granted to anyone to use this software for any purpose, * including commercial applications, and to alter it and redistribute it * freely, subject to the following restrictions: * * 1. The origin of this software must not be misrepresented; you must not * claim that you wrote the original software. If you use this software * in a product, an acknowledgment in the product documentation would be * appreciated but is not required. * 2. Altered source versions must be plainly marked as such, and must not be * misrepresented as being the original software. * 3. This notice may not be removed or altered from any source distribution. */ // Adapted from BulletXNA 73b2e1b9: namespace isolation, no XNA rendering, one type per file. #nullable disable #pragma warning disable CS1591, CS0168, CS0219, CS0414, CS0660, CS0661, CS0659, CS0693, CS8981, CS0108, CS0114 using System; using System.Collections.Generic; using System.Diagnostics; using HumanoidRetargeter.Core.Formats.Mmd.Bullet.BulletCollision; using HumanoidRetargeter.Core.Formats.Mmd.Bullet.LinearMath; namespace HumanoidRetargeter.Core.Formats.Mmd.Bullet.BulletDynamics; internal class WheelContactPoint { public RigidBody m_body0; public RigidBody m_body1; public IndexedVector3 m_frictionPositionWorld; public IndexedVector3 m_frictionDirectionWorld; public float m_jacDiagABInv; public float m_maxImpulse; public WheelContactPoint(RigidBody body0, RigidBody body1, ref IndexedVector3 frictionPosWorld, ref IndexedVector3 frictionDirectionWorld, float maxImpulse) { m_body0 = body0; m_body1 = body1; m_frictionPositionWorld = frictionPosWorld; m_frictionDirectionWorld = frictionDirectionWorld; m_maxImpulse = maxImpulse; float denom0 = body0.ComputeImpulseDenominator(ref frictionPosWorld, ref frictionDirectionWorld); float denom1 = body1.ComputeImpulseDenominator(ref frictionPosWorld, ref frictionDirectionWorld); float relaxation = 1f; m_jacDiagABInv = relaxation / (denom0 + denom1); } }